Quadrupolar mass analysis device

Abstract

Disclosed is a quadrupolar mass analysis device provided with direct-current voltage sources (62, 63) having response characteristics wherein the response time of the direct-current voltage is shorter than the time required when an ion having the maximum mass-to-charge ratio among ions introduced to a quadrupolar mass filter (2) passes through the quadrupolar mass filter (2). Main rod electrodes (31-34) and front rod electrodes (41-44) are connected via primary differentiation circuits (65, 66). Thus, in the transient state of voltage variation in association with the changing of mass-to-charge ratios, among ions entering the quadrupolar mass filter (2), ions having a low m / z can be eliminated in a front electrode portion (4), and ions having a high m / z can be eliminated in a main electrode portion (3). Accordingly, a large amount of ions can be prevented from passing through the quadrupolar mass filter (2) and entering an ion detector (5).

Description

technical field [0001] The present invention relates to a quadrupole mass spectrometer using a quadrupole mass filter as a mass analyzer for separating ions derived from a sample according to the mass-to-charge ratio (m / z). Background technique [0002] Generally, in a quadrupole mass spectrometer, various ions generated from a sample are introduced into a quadrupole mass filter, and only ions with a specific mass-to-charge ratio are selectively passed through, and the detector is used to detect the ions that pass through. Detection is performed to obtain an intensity signal corresponding to the amount of ions. [0003] The quadrupole mass filter is composed of four rod electrodes arranged parallel to each other around the ion optical axis, and a voltage obtained by adding a DC voltage and a high-frequency voltage (AC voltage) is applied to each of the four rod electrodes. The mass-to-charge ratio of ions that can pass through the quadrupole mass filter depends on the high-...

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Problems solved by technology

[0011] As mentioned above, if ions pass through the quadrupole mass filter in excess when switching the transition state of the mass-to-charge ratio, there is a possibility that the degradation of the detector will be accelerated due to the excess ions being incident on the detector

In addition, in a three-connected quadrupole (series) type mass spectrometer (for example, refer to Patent Document 2) in which a collision cell is provided between the front and rear quadrupole mass filters, if the If the amount of ions is too much, the excess ions will stay inside the collision cell, which may cause crosstalk, or reduce the SN ratio and sensitivity, etc.

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